1. Field of the Invention
This invention generally relates to optical signal processing cards in add/drop multiplexers. More specifically, this invention relates to a high-speed optical signal processing card that incorporates electrical and optical components on a single card in an add/drop multiplexer.
2. Description of the Related Art
Optical networks are increasing in importance, and high speed digital signals are commonly transmitted using Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) standards at speeds ranging from 51.84 Mb/s (OC-1) to 9.95 Gb/s (OC-192). A wide range of equipment incorporates SONET/SDH transmission functionality, including add/drop multiplexers (ADMs) which allows digital transmission signals to be removed or inserted from incoming/outgoing optical streams.
Because space is limited in telecommunications equipment, it is essential to be able to provide the maximum amount of functionality in the minimum volume. As an example, optical cards in add/drop multiplexers must operate at very high speeds and must contain powerful optical components, but should not occupy multiple slots within the add/drop multiplexer. This can be particularly challenging at OC-192 operating speeds, where 10 gigabits per second signals must be routed around the card, and where high power optical components must be utilized. In addition, crosstalk and thermal issues must be addressed.